In vivo exposure to high or low cortisol has biphasic effects on inflammatory response pathways of human monocytes.
BACKGROUND
Recent studies demonstrate that glucocorticoids (GCs) have both supportive (stimulatory) and suppressive effects on immune responses, depending upon the GC concentration. Since some GC effects on inflammation are stimulatory, we hypothesized that acute in vivo GC depletion would decrease inflammatory responses of human monocytes.


METHODS
Monocytes were isolated from healthy volunteer participants before and after in vivo treatment with; 1) IV saline, 2) IV high dose hydrocortisone (8 microg x kg(-1) x min(-1)) followed by oral hydrocortisone overnight, and 3) oral RU486 (200 mg at 0400 and 1600 h) to block the intracellular GC receptor and IV etomidate (1.5 mg x kg(-1) x h(-1)) for 12 h to prevent compensatory adrenal cortisol synthesis. Plasma adrenocorticotropic hormone, plasma, and salivary cortisol were measured serially. Monocytes were tested for; 1) cytokine responses, 2) expression of CD163, CD119, and CD54, and 3) mRNA levels of GC-responsive inflammatory mediators. All measurements were made with and without in vitro stimulation of monocytes by lipopolysaccharide.


RESULTS
Cortisol and adrenocorticotropic hormone measurements demonstrated effective manipulation of in vivo cortisol. In vivo hypercortisolemia and in vivo GC depletion had reciprocal effects on monocyte mRNA levels of 4 important GC-responsive molecules: 1) GC receptor, CD163, interleukin-10, and suppressor of the cytokine synthesis-3. Monocyte cytokine responses and protein expression were not affected by GC depletion. CD163 expression was increased by hypercortisolemia.


CONCLUSIONS
Short-term GC depletion affects mRNA levels of GC-responsive molecules but does not affect monocyte protein expression or cytokine responses.
Yeager
Mark P
MP
Department of Anesthesiology, Dartmouth-Hitchcock Medical Center, 1 Medical Center Dr., Lebanon, NH 03756, USA. mark.p.yeager@hitchcock.org
Pioli
Patricia A
PA
Wardwell
Kathleen
K
Beach
Michael L
ML
Martel
Peter
P
Lee
Hong K
HK
Rassias
Athos J
AJ
Guyre
Paul M
PM
D000293:Adolescent; D000305:Adrenal Cortex Hormones / Q000097:blood; D000324:Adrenocorticotropic Hormone / Q000097:blood; D000328:Adult; D000893:Anti-Inflammatory Agents / Q000494:pharmacology; D005045:Etomidate / Q000494:pharmacology; D005260:Female; D005938:Glucocorticoids / Q000494:pharmacology; D006801:Humans; D006854:Hydrocortisone / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D007249:Inflammation / Q000503:physiopathology*; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D015735:Mifepristone / Q000494:pharmacology; D009000:Monocytes / Q000187:drug effects / Q000502:physiology*; D011965:Receptors, Glucocorticoid / Q000187:drug effects / Q000235:genetics
D000305:Adrenal Cortex Hormones; D000893:Anti-Inflammatory Agents; D005938:Glucocorticoids; D011965:Receptors, Glucocorticoid; D015735:Mifepristone; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone; D005045:Etomidate